Association between severity of obstructive sleep apnea-hypopnea syndrome and coronary microvascular function in patients with hypertension

Objective To investigate the association between the severity of obstructive sleep apnea-hypopnea syndrome (OSAHS) and coronary microvascular function in patients with hypertension.

Methods A total of 262 hypertensive patients hospitalized in the Department of Cardiology, Xuzhou Central Hospital from September 2024 to September 2025 were enrolled. All patients underwent portable sleep monitoring. Based on the apnea-hypopnea index (AHI), patients were divided into four groups: without OSAHS group (AHI＜5 events/hour), mild OSAHS group ( AHI 5 to ＜15 events/hour), moderate OSAHS group (AHI 15 to≤30 events/hour), and severe OSAHS group (AHI＞30 events/hour). To assess coronary microcirculatory function, coronary flow velocity reserve (CFVR) was obtained via stress echocardiography in 55 patients, and the angiographic microcirculatory resistance index (AMR) was calculated using quantitative flow ratio (QFR) technology based on coronary angiography in 224 patients. Clinical data, sleep monitoring parameters, CFVR, AMR, and relevant laboratory data including high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) were collected. Multivariate linear regression analysis was performed to assess the association between OSAHS severity and coronary microvascular function.

Results  Compared with without OSAHS group, mild OSAHS group, and moderate OSAHS group, in the severe OSAHS group, CFVR was significantly lower (1.80±0.19 vs 2.46±0.25, 2.41±0.27, 2.07±0.23,F=18.171,all P＜0.05), and the left anterior descending artery AMR was significantly higher (3.40±0.34 vs 2.75±0.39, 2.73±0.47, 3.00±0.38 mmHg·s·cm^-1, F=24.935,all P＜0.05). Furthermore, the left circumflex artery AMR, IL-6, and hsCRP levels in the severe OSAHS group were also significantly higher than those in the other groups (P＜0.05). Compared with the without OSAHS and mild OSAHS groups, the moderate OSAHS group showed a significantly lower CFVR, while its left anterior descending artery AMR, left circumflex artery AMR, and IL-6 levels were significantly elevated (P＜0.05). Multivariate linear regression analysis revealed that increased OSAHS severity was an independent predictor of decreased CFVR (B = –0.234, P＜0.001) and increased left anterior descending artery AMR (B = 0.217, P＜0.001).

Conclusion Among hypertensive patients, comorbid moderate-to-severe OSAHS is associated with more severe coronary microcirculatory dysfunction, and the severity of this dysfunction increases with the grade of OSAHS.